Machine for drilling holes in right-angular work surfaces

ABSTRACT

A drilling machine comprises a ram movable up and down on a carriage slidably mounted on a horizontal crossrail. A toolhead is mounted on the bottom end of the ram for pivotal movement about a horizontal axis at right angles with the crossrail and is pivoted to a desired angular position by a first drive shaft within the ram via bevel gearing. Rotatably mounted in the toolhead for rotation about an axis lying in a vertical plane is a toolholder which rigidly supports a drill and which is driven from a second drive shaft within the ram via bevel gearings. Preferably, the machine further comprises a rack-and-pinion mechanism driven from the second drive shaft for securely but releasably locking a turning tool at the bottom end of the ram, so that the machine can be used also for turning operation as a workpiece is rotated on a turntable. This turntable is of course held stationary during drilling operation.

BACKGROUND OF THE INVENTION

This invention relates to machine tools and is directed morespecifically to a machine for drilling holes in right-angular surfacesof a workpiece. The invention also specifically deals with such adrilling machine which readily lends itself to various turningoperations as well.

Heretofore, for creating holes in two right-angular surfaces of aworkpiece, there has been usually employed a drilling machine comprisingtwo toolheads each having a rotary cutting tool for drilling one of theworkpiece surfaces. Such a dual-head drilling machine requires separatemeans for providing rotary and feed motion for the respective cuttingtools, as well as separate means for adjusting the positions of therespective tools with respect to a workpiece. As a consequence, thedrilling machine has been unnecessarily complex in construction andexpensive of manufacture.

SUMMARY OF THE INVENTION

It is an object of this invention to provide a simplified, inexpensivemachine tool which has only one toolhead but which is capable ofproducing holes at desired points on right-angular surfaces of aworkpiece.

Another object of the invention is to provide a machine tool of theabove described character which is readily adaptable for a variety ofturning operations.

Briefly, this invention provides, in a machine tool of the typespecified, the combination comprising a crossrail extending parallel tothe surface of a table on which is to be mounted a workpiece to bemachined. A carriage movable along the crossrail supports a ram which isitself movable toward and away from the table relative to the carriage.On one end of the ram, disposed opposite to the table, there is mounteda toolhead which is pivotable relative to the ram about an axis at rightangles with the crossrail and parallel to the surface of the table.Rotatably mounted in the toolhead is a toolholder which rigidly supportsa rotary cutting tool such as a drill and which is rotatable therewithabout an axis lying in a plane parallel to the crossrail and at rightangles with the surface of the table. The combination according to theinvention further comprehends means for pivoting the toolhead relativeto the ram, and means for imparting rotation to the toolholder andtherefore to the cutting tool supported thereby.

Thus, according to this invention, the single rotary cutting toolrotatably supported by the pivotal toolhead via the toolholder can bepivoted to and locked in a disposition either perpendicular or parallelto the surface of the table. Since the desired rotary and feed motioncan be imparted to the cutting tool in either disposition, holes can beproduced in right-angular surfaces of a workpiece on the table by use ofthe single cutting tool.

According to a further feature of this invention, means are provided forsecurely but releasably locking a turning tool in position on the ram.In the preferred embodiment of the invention, the locking means includea rack-and-pinion mechanism actuated via a clutch by a drive shaftwhich, during drilling operation, drives the rotary cutting tool. Whenthe turning tool is mounted in position on the ram, the clutch becomesengaged to permit the drive shaft to actuate the rack-and-pinionmechanism, whereupon the latter operates to secure the turning tool tothe ram by weding action. The aforesaid table is made rotatable topermit rotation of a workpiece relative to the turning tool, so that themachine tool according to the invention can be conditioned for turningoperation simply by mounting the turning tool in position on the ram.The table will be referred to as the turntable in the subsequentdescription of the preferred embodiment.

The above and other objects, features and advantages of this inventionand the manner of attaining them will become more apparent, and theinvention itself will best be understood, upon consideration of thefollowing description taken together with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevational view of a drilling and turning machineconstructed in accordance with the novel concepts of this invention;

FIG. 2 is a right hand side elevational view of the machine of FIG. 1;

FIG. 3 is an enlarged, fragmentary vertical sectional view taken alongthe line 3--3 of FIG. 1;

FIG. 4 is a fragmentary vertical sectional view showing, on a still moreenlarged scale, that portion of FIG. 3 which is surrounded by a circle;and

FIG. 5 is a horizontal sectional view, also on a still more enlargedscale, taken along the line 5--5 of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In the accompanying drawings this invention is shown adapted for acombined drilling and turning machine. With reference first to FIGS. 1and 2, the drilling and turning machine broadly comprises a turntable 10rotatably supported in a base or pedestal 12 of generally boxlike shape,a crossrail 14 mounted on a pair of columns 16 erected on the base andextending horizontally or parallel to the surface of the turntable, acarriage 18 slidably mounted on the crossrail for movement therealong, aram 20 mounted on the carriage for movement toward and away from aworkpiece W on the turntable, a toolhead 22 having a rotary cutting toolor drill 24 and pivotally mounted on the bottom end of the ram, and aturning tool 26 removably mounted on the bottom end of the ram forinterchangeable use with the drill. It will be noted from the drawingsthat the machine is of substantially symmetrical construction, unlikethe prior art dual-head drilling machine mentioned previously, so thatit will suffer little from possible thermal expansion or contractionwith changes in ambient temperature.

The turntable 10 may be rotatably mounted on a carriage 28 which isreciprocally movable relative to the base 12 between a working positionindicated by the solid lines in FIG. 2 and a standby position indicatedby the dot-and-dash lines in the same drawing. Such reciprocating motionof the carriage 28 and therefore of the turntable 10 is effected by aservomotor shown at 30.

FIGS. 1 and 2 further illustrate a motor 32 for rotating the turntable10, a servomotor 34 for moving the carriage 18 along the crossrail 14,and a servomotor 36 for moving the ram 20 toward and away from theworkpiece W.

As illustrated in greater detail in FIG. 3, the toolhead 22 issubstantially integrally provided with a sleeve 38 which is rotatablyreceived in a hole 40 formed in the recessed front surface 42 of the ram20. The toolhead 22 is therefore pivotable relative to the ram 20 aboutthe axis of the sleeve 38, which axis extends at right angles with thecrossrail 14 and parallel to the surface of the turntable 10.

For thus pivoting the toolhead 22, there is provided a first drive shaft44 arranged vertically within the ram 20 and terminating in a bevelpinion 46. This bevel pinion is in mesh with a bevel gear 48 coaxiallysurrounding the sleeve 38 and rigidly fastened thereto. The rotation ofthe first drive shaft 44 can therefore be transmitted through the bevelgearing 46, 48 to the sleeve 38 for pivoting the toolhead 22 to adesired angular position relative to the ram 20.

Rotatably supported within the toolhead 22 is a toolholder 50 securelyholding the drill 24, with the toolholder being rotatable with the drillabout an axis lying in a plane parallel to the cross rail 14 and atright angles with the surface of the turntable 10. This toolholder 50 issubstantially integrally provided with a bevel gear 52 which is in meshwith a bevel gear 54 formed at the left hand end, as seen in FIG. 3, ofa spindle 56 rotatably received in the sleeve 38. The right hand end ofthe spindle 56, projecting out of the sleeve 38, is also formed into abevel gear 58 which is in mesh with a bevel pinion 60 formed at thebottom end of a second drive shaft 62 rotatably supported within the ram20 in side-by-side relationship to the first drive shaft 44.

The rotation of the second drive shaft 62 is therefore transmitted tothe spindle 56 through the bevel gearing 58, 60 and thence to thetoolholder 50 through the bevel gearing 52, 54. The drill 24 can thus bedriven from a suitable drive source, not shown, connected to the seconddrive shaft 62.

Besides driving the drill 24, the second drive shaft 62 is also utilizedfor releasably locking the turning tool 26 in its working position atthe bottom end of the ram 20 through the following means.

Under the second drive shaft 62 and in axial alignment therewith, apinion shaft 64 is supported by a bracket 66 via bearings 68 and 70 soas to be both rotatable and movable endwise toward and away from thesecond drive shaft. The pinion shaft 64 terminates at its top in ajournal 72 of reduced diameter neatly received in the bearing 68 whichis slidably fitted in an axial bore 74 of the second drive shaft 62, asillustrated on an enlarged scale in FIG. 4. At its bottom the pinionshaft 64 terminates in a push button 76, also of reduced diameter,slidably extending through a hole 78 formed in the bottom of the ram 20.The pinion shaft 64 is biased away from the second drive shaft 62 by ahelical compression spring 80, so that when the turning tool 26 is notmounted in its working position shown in FIG. 3, the push button 76projects downwardly out of the hole 78 under the bias of the compressionspring 80.

As best seen in FIG. 4, a jaw clutch generally labelled 82 is providedfor connecting the second drive shaft 62 to the pinion shaft 64 indriving relationship when the latter is moved upwardly by the turningtool 26 via the push button 76 against the bias of the compressionspring 80.

The jaw clutch 82 comprises a first clutch face 84 formed on the bottomend of the second drive shaft 62, or on the bevel pinion 60, and asecond clutch face 86 formed on the opposed top end of a sleeve 88 onthe pinion shaft 64 for interlocking engagement with the first clutchface. The sleeve 88 is splined at 90 to the pinion shaft 64 so as to berotatable simultaneously therewith but movable up and down relative tosame. A helical compression spring 92 extends between the bottom end ofthe sleeve 88 and a step 94 of the pinion shaft 64 for biasing thesleeve upwardly relative to the pinion shaft, and the upward motion ofthis sleeve is limited by a stop ring 96 fixedly mounted between the topshoulder of the pinion shaft 64 and the bearing 68.

Thus, upon upward motion of the pinion shaft 64, the jaw clutch 82becomes engaged to transmit the rotation of the second drive shaft 62 tothe sleeve 88 and thence to the pinion shaft 64. Upon removable of theturning tool 26, the jaw clutch 82 becomes disengaged as then the pinionshaft 64 moves downwardly under the bias of the compression spring 80together with the sleeve 88, stop ring 96 and bearing 68.

As will be seen from FIGS. 3 and 5, the pinion shaft 64 is formed into apinion 98 at its bottom end portion. The pinion 98 is in constant meshwith a rack 100 slidably mounted within the ram 20 for movement into andout of engagement with a base portion 102 of the turning tool 26received in a mounting hole 104 formed in the bottom of the ram. Therack 100 is adapted to serve as a wedge which, when driven intoengagement with the base portion 102 of the turning tool 26 by thepinion 98 upon the engagement of the jaw clutch 82, is effective tosecurely lock the turning tool in its working position by wedgingaction.

OPERATION

Although the operation of the combined drilling and turning machineaccording to the invention is believed clearly apparent from theforegoing description, further amplification will be made in thefollowing brief summary of such operation. The machine can beconditioned for drilling operation simply by removing the turning tool26 from the ram 20. For drilling a hole in the top surface of theworkpiece W on the turntable 10, the toolhead 22 may be pivoted to suchan angular position relative to the ram 20 that the drill 24 is disposedvertically as shown in FIGS. 1 through 3.

The second drive shaft 62 may then be set in rotation to drive the drill24 via the bevel gearing 58, 60, the spindle 56, the bevel gearing 52,54, and the toolholder 50. The top surface of the workpiece W can bedrilled as the revolving drill 24 is fed into the workpiece mounted onthe turntable 10 in its working position. The rotation of the seconddrive shaft 62 is not transmitted to the pinion shaft 64 since now thejaw clutch 82 is disengaged, with the pinion shaft held away from thesecond drive shaft under the bias of the compression spring 80.

For drilling another hole in a side surface of the workpiece W at anangle of 90° from its top surface, the first drive shaft 44 may be setin rotation to pivot the toolhead 22 about the axis of the sleeve 38 viathe bevel gearing 46, 48 until the drill 24 is turned 90° in eitherdirection from its vertical disposition. The position of the drill 24with respect to the workpiece W may also be adjusted as required bymoving the carriage 18 and the ram 20. The side surface of the workpiececan be drilled as the drill 24 is then both rotated and fed into theworkpiece.

For the use of the machine for turning operation, the turning tool 26may be mounted in its working position best shown in FIG. 3 by insertingits base portion 102 into the mounting hole 104 at the bottom of the ram20. As the turning tool base portion 102 is inserted fully into themounting hole 104, the push button 76 is pushed into the hole 78 to movethe pinion shaft 64 upwardly against the bias of the compression spring80, so that the jaw clutch 82 becomes engaged to connect the seconddrive shaft 62 to the pinion shaft 64 in driving relationship.

As the second drive shaft 62 is subsequently set in rotation, therefore,the pinion shaft 64 is thereby rotated via the sleeve 88, and by theconsequent rotation of the pinion 98, the rack 100 is forced intoengagement with the base portion 102 of the turning tool 26 for securelylocking same in position on the ram 20 by wedging action. A desiredturning operation can be performed on the workpiece W as same is rotatedby the turntable 10.

It should be appreciated that since the turning tool 26 is mounteddirectly on the ram 20 and securely locked in position by therack-and-pinion mechanism driven from the second drive shaft 62, theturning tool can be held rigidly supported during turning operation, sothat the workpiece can be cut to the desired shape with a high degree ofaccuracy. In practice, turning tools of various types and sizes may beprepared for interchangeable use, thereby adapting the machine for avariety of turning operations including internal and external cuttings.

While the machine tool in accordance with this invention has been shownand described in terms of its preferred form, it is understood that theinvention itself is not to be restricted by the exact details of thisdisclosure, since numerous modifications and adaptations within theusual knowledge of those skilled in the art may be resorted to withoutdeparting from the spirit or scope of the invention as expressed in thefollowing claims.

What is claimed is: .[.1. In a machine tool, in combination, a table, acrossrail extending parallel to the surface of said table, a carriagemounted on said crossrail for movement therealong, means for moving saidcarriage along said crossrail, a ram mounted on said carriage formovement toward and away from said table, said ram being further movablewith said carriage along said crossrail, means for moving said ramtoward and away from said table, a toolhead pivotally mounted on thatend of said ram which is disposed opposite to said table, a toolholderrotatably supported by said toolhead for rotation about an axis lying ina plane parallel to said crossrail and at right angles with the surfaceof said table, means for imparting rotation to said toolholder, a rotarycutting tool supported by said toolholder for simultaneous rotationtherewith, said toolhead being pivotable relative to said ram about anaxis at right angles with said crossrail and parallel to the surface ofsaid table, and means for pivoting said toolhead relative to said ramwherein said tool has a first operative position such that its axis isperpendicular to the plane of said table and said tool has a secondoperative position such that its axis is at an angle other than a rightangle with respect to the plane of said table..]. .[.2. In a machinetool, in combination, a table, a crossrail extending parallel to thesurface of said table, a carriage mounted on said crossrail for movementtherealong, means for moving said carriage along said crossrail a rammounted on said carriage for movement toward and away from said table,said ram being further movable with said carriage along said crossrail,means for moving said ram toward and away from said table, a toolheadhaving a sleeve by which said toolhead is pivotally supported on thatend of said ram which is disposed opposite to said table, a toolholderrotatably supported by said toolhead for rotation about an axis lying ina plane parallel to said crossrail and at right angles with the surfaceof said table, a spindle rotatably mounted within said sleeve, means forimparting rotation to said spindle, means for imparting the rotation ofsaid spindle to said toolholder, a rotary cutting tool supported by saidtoolholder for simultaneous rotation therewith, said toolhead beingpivotable relative to said ram about the axis of said sleeve extendingat right angles with said crossrail and parallel to the surface of saidtable, and means for pivoting said toolhead via said sleeve relative tosaid ram wherein said tool has a first operative position such that itsaxis is perpendicular to the plane of said table and said tool has asecond operative position such that its axis is at an angle other than aright angle with respect to the plane of said table..]. .[.3. In amachine tool, in combination, a table, a crossrail extending parallel tothe surface of said table, a carriage mounted on said crossrail formovement therealong, means for moving said carriage along saidcrossrail, a ram mounted on said carriage for movement toward and awayfrom said table, said ram being further movable with said carriage alongsaid crossrail, means for moving said ram toward and away from saidtable, a toolhead substantially integrally provided with a sleeverotatably supported at that end of said ram which is disposed oppositeto said table, said toolhead being pivotable relative to said ram aboutthe axis of said sleeve extending at right angles with said crossrailand parallel to the surface of said table, a first drive shaft withinsaid ram, first bevel gear means for imparting the rotation of saidfirst drive shaft to said sleeve and thus for pivoting said toolheadrelative to said ram, a toolholder rotatably supported by said toolheadfor rotation about an axis lying in a plane parallel to said crossrailand at right angles with the surface of said table, a spindle rotatablymounted within said sleeve, a second drive shaft within said ram, secondbevel gear means for imparting the rotation of said second drive shaftto said spindle, third bevel gear means for imparting the rotation ofsaid spindle to said toolholder, and a rotary cutting tool supported bysaid toolholder for simultaneous rotation therewith..].
 4. In a machinetool, in combination, a turntable, a crossrail extending parallel to thesurface of said turntable, a carriage mounted on said crossrail formovement therealong, means for moving said carriage along saidcrossrail, a ram mounted on said carriage for movement toward and awayfrom said turntable, said ram being further movable with said carriagealong said crossrail, means for moving said ram toward and away fromsaid turntable, a toolhead substantially integrally provided with asleeve rotatably supported at that end of said ram which is disposedopposite to said turntable, said toolhead being pivotable relative tosaid ram about the axis of said sleeve extending at right angles withsaid crossrail and parallel to the surface of said turntable, a firstdrive shaft within said ram, means for imparting the rotation of saidfirst drive shaft to said sleeve and thus for pivoting said toolheadrelative to said ram, a toolholder rotatably supported by said toolheadfor rotation about an axis lying in a plane parallel to said crossrailand at right angles with the surface of said turntable, a spindlerotatably mounted within said sleeve, a second drive shaft within saidram, means for imparting the rotation of said second drive shaft to saidspindle, means for imparting the rotation of said spindle to saidtoolholder, a rotary cutting tool supported by said toolholder forsimultaneous rotation therewith, a turning tool removably mounteddirectly on said end of said ram, locking means adapted to be actuatedby said second drive shaft for securely but releasably locking saidturning tool in position on said ram, and means for rotating saidturntable relative to said turning tool.
 5. The machine tool as recitedin claim 4, wherein said locking means comprises a pinion shaft havingteeth formed thereon and rotatably supported within said ram in axialalignment with said second drive shaft, said pinion shaft being furthermovable endwise toward and away from said second drive shaft, resilientmeans yieldably urging said pinion shaft away from said second driveshaft, said pinion shaft being adapted to be moved toward said seconddrive shaft against the force of said resilient means when said turningtool is mounted in position on said ram, clutch means arranged betweensaid second drive shaft and said pinion shaft and adapted to be engagedupon movement of the latter toward the former, and a rack meshing withsaid teeth on said pinion shaft and serving as a wedge movable into andout of engagement with said turning tool, whereby upon engagement ofsaid clutch means, said rack is moved into engagement with said turningtool for securely locking same in position on said ram by wedgingaction.
 6. The machine tool as recited in claim 5, wherein said clutchmeans comprises a first clutch face formed on said second drive shaft, asecond sleeve splinedly mounted on that end of said pinion shaft whichis disposed opposite to said second drive shaft, and second sleeve beingrotatable simultaneously with said pinion shaft but movable endwiserelative to same, a second clutch face formed on one end of said secondsleeve for interlocking engagement with said first clutch face, secondresilient means yieldably urging said second sleeve toward said seconddrive shaft relative to said pinion shaft, and stop means formed on saidend of said pinion shaft for limiting the motion of said second sleevetoward said second drive shaft. .[.7. The machine tool as recited inclaim 1 wherein the axis of said toolhead is parallel to the plane ofsaid table when said toolhead is in its second operative position..]..[.8. The machine tool as recited in claim 1 further including a turningtool removably mounted directly to the end of said ram..]. .[.9. Themachine tool as recited in claim 8 further comprising locking means forreleasably locking said turning tool in position on said ram, and meansfor rotating said turntable relative to said turning tool..]. .[.10. Themachine tool as recited in claim 2 wherein the axis of said toolhead isparallel to the plane of said table when said toolhead is in its secondoperative position..]. .[.11. The machine tool as recited in claim 2further including a turning tool removably mounted directly to the endof said ram..]. .[.12. The machine tool as recited in claim 11 furthercomprising locking means for releasably locking said turning tool inposition on said ram, and means for rotating said turntable relative tosaid turning tool..].